Lieutenant Commander Kurt Ambrose (UNSCMID: 045888947, civilian identification number: 56522-026-LDR5685), born Kurt M. Trevelyan and formerly known as SPARTAN-051, was a SPARTAN-II supersoldier. Formerly the leader of Green Team, he was close to many of the other Spartans, before he went missing during a mission in 2531. Although the other Spartans were led to believe that Kurt had died, he was actually recruited by ColonelJames Ackerson to spearhead the SPARTAN-III program.[4]

The name "Ambrose" was given to him by Colonel Ackerson after his abduction, due to the fact Kurt actually could not remember his full name as a result of extensive mental conditioning involved in the SPARTAN-II program.[5]

During his training, Kurt quickly proved himself to be considered one of the program's top candidates. Both Dr. Halsey and Chief Mendez identified him as one of four emerging leaders within the Spartan-II group, along with Jerome-092, Fred-104, and John-117. Chief Mendez expressed his belief the most strongly in Kurt as having the skills to lead the entire Spartan-II group, although Halsey disagreed, instead believing John would fulfill that role.[1]

Kurt's leadership skills were correctly observed, as he later became one of the earliest known leaders of the Spartan-IIs' Green Team, which would often beat John's Blue Team in field exercises.[6]

Soon after, Kurt and Blue Team participated in an extravehicular mission to investigate reported suspicious activity at Construction Platform 966A. During the mission, Kurt approached a ruptured Shaw-Fujikawa Translight Engine when his T-PACK "malfunctioned", sending him spinning away into deep space. He was listed as missing in action and presumed dead. However, Kurt was recovered by ONI, which had manufactured the whole mission to allow Colonel James Ackerson to recruit the Spartan with new orders to train the next generation of SPARTANs. While his former identity as SPARTAN-051 remained as MIA, Kurt was given a new surname and an officer's commission, as Lieutenant, Junior Grade.[8] Kurt Ambrose was then sent to the classified planet Onyx to train the SPARTAN-IIIs with CPO Mendez.[9] Over time, he was promoted for his successful efforts in training the new Spartans, having reached the rank of Lieutenant Commander by 2545.[10]

Kurt cared deeply for each of the Spartan companies he trained, and was profoundly distraught by deaths of the entire SPARTAN-III Alpha Company in Operation: PROMETHEUS. Attributing their demise to the loss of unit cohesion, he vowed not to let future Spartan generations share their fate and focused on honing the Spartans' teamwork capabilities when training Beta Company.[11] Nevertheless, Beta Company was also wiped out almost entirely in Operation: TORPEDO despite Kurt's efforts.

After the destruction of Beta Company, Kurt managed to have the two remaining survivors, Tom-B292 and Lucy-B091 reassigned to accompany him and Mendez in training Gamma Company; he had to appeal to Vice Admiral Parangosky who eventually agreed—over Ackerson's objections. The two would become Kurt's top adjutants over the years.[12] Additionally, while the SPARTAN-IIIs were initially intended as cannon fodder, Kurt and Mendez recognized that a number of the trainees were too skilled to be wasted on suicide missions, so they removed them from their respective companies before they were wiped out, gave them MJOLNIR armor, and assigned them to other units, some of them becoming NOBLE Team.[13]

With Gamma Company, whom he came to regard as the "finest Spartans ever",[12] Kurt secretly added a series of illegal drugs to the augmentation procedures in order to heighten the Spartans' aggressive response, giving them a better chance of survival in battle. This was against the recommendations of Onyx's AI Deep Winter, who was concerned with the Spartans' well-being.[14]

At the outbreak of hostilities in Zone 67 on October 31, 2552, Kurt regrouped with Tom-B292 and Lucy-B091 at Camp Currahee and willfully used the SPI armor used by the SPARTAN-IIIs instead of his superior MJOLNIR armor as he told Lucy-B091 that he was one of them now, a SPARTAN III, once again displaying his utmost concern for the morale of his team.[15]

Later on during the conflict, he reunited with Dr. Halsey and Kelly-087. Dr. Halsey, along with the help of the ONI AIEndless Summer, was able to send a message through slipspace by using Cortana's original broadcast from Installation 05 as a carrier wave. She asked Fleet AdmiralHood to send Spartans to Onyx in order to acquire possible Forerunner technology.[16] The SPARTAN-IIs on Earth, Fred-104, Will-043, and Linda-058 infiltrated and captured a Covenant vessel, the Bloodied Spirit, which they took to Onyx where they met Kurt. Kurt then led the Spartans on a mission into the newly uncovered Forerunner city on Onyx to locate the technology Dr. Halsey had been looking for.[17]

The mission was abruptly complicated due to the Covenant fleet led by Voro Nar 'Mantakree locating Onyx and learning of the humans' mission. Kurt and his team managed to acquire information pertaining to Onyx in a map room, where it dawned to them that the planet was actually an artificial structure.[18] Dr. Halsey convinced Kurt to push on into a room in Onyx's core, deducing that it held something of significant importance to the Forerunners.[19] After escaping Covenant forces using Onyx's teleportation grid, were redirected by Zone 67's AI Endless Summer to destroy a Sentinel manufacturing facility. After destroying the factory they located the missing Spartans of Team Katana, who had been placed in Forerunner slipspace field pods.[20]

Before they proceeded further toward the "shield world" which, according to Dr. Halsey, held the Forerunner technologies they sought, Kurt confronted the doctor, realizing she was not telling the full truth behind her mission. After first inquiring Kurt about the specifics of the Spartan-IIIs' augmentations, Dr. Halsey revealed Kurt her true reasons behind her quest to Onyx; instead of recovering Forerunner technology, she intended to shelter the Spartans in the shield world inside Onyx's core, predicting that the UNSC would lose the war.[21] Despite this revelation, Kurt decided they continue inside the core room, retrieve any useful technologies and then escape. In case they failed, they could use the pair of FENRIS nuclear warheads they had brought with them to ensure the technology did not fall into Covenant hands.[22]

Inside the vast core room antechamber of Onyx, Kurt and the Spartans assumed defensive positions around the slipspace portal leading to the shield world in order to prevent the Covenant from accessing it. As Covenant forces started translocating inside the chamber in increasingly large numbers, it quickly became clear that the humans would soon be overrun. Kurt then ordered the others to enter the slipspace rift before it closed, while he opted to stay behind and detonate the warheads. Kurt commissioned Fred as a Lieutenant, Junior Grade before sending them to the shield world in order to give the remaining Spartans a leader to follow.[23] Eventually, only Tom-B292 and Lucy-B091 remained, hesitant to leave Kurt behind. Knowing they could not be convinced otherwise, Kurt knocked Tom out with a punch and hefted him into the rift. Though reluctant, Lucy finally obeyed Kurt's orders and stepped through the portal as well.[24]

Kurt, now alone and mortally injured from a previous firefight, listed the Spartans fallen in the battle as MIA—including himself, alongside his former identity as SPARTAN-051. He successfully delayed the Covenant forces until the slipspace portal had closed. In his death throes, Kurt had a hallucination of all the fallen SPARTAN-IIs and SPARTAN-IIIs by his side, nodding and giving him the thumbs-up signal, forging his resolve to complete his one final task. Fleet Master Voro Nar 'Mantakree then approached him, gloating that once the "demon" was dead, the Covenant would reopen the shield world portal. Laughing in determination, Kurt replied "Die? Didn't you know? Spartans never die" and detonated the warheads, wiping out the Covenant army and thus preventing the Covenant from following his comrades and gaining access to the technologies inside the shield world.[25]

Kurt died in the end as a brilliant commander in the eyes of those he had known, and as a noble hero who cared deeply for his SPARTAN-IIIs and SPARTAN-IIs as comrades and friends, John-117 included. After the conclusion of the Human-Covenant War in 2553, his still-intact Spartan armor transponder was detected by the UNSC Glamorgan in the debris field that was formerly Onyx, leading to the rescue of remaining UNSC personnel in the shield world.[26] In honor of Kurt, Dr. Halsey, with AdmiralParangosky's approval, named the micro Dyson sphere "ONI Research Facility Trevelyan". At first, Chief Mendez suggested using the name "Ambrose", but Halsey opted that they use Kurt's real name.[27]

Kurt was unusually sociable for a Spartan and considered the well being of his teammates more important than the whims of his commanding officers. While the rest of his teammates were closely guarded and private unless around other Spartans, Kurt spent a considerable amount of time making friends, such as with the drill instructors. This made some of his fellow Spartans uneasy, as they were not comfortable with a leader who was so easily distracted. Despite these perceptions, Kurt proved himself to be an extremely proficient leader.[6] After his indoctrination into the SPARTAN-III program, his leadership qualities became even more pronounced.[28] While training the Spartan-IIIs he took great pride in them and their losses traumatized him.

Kurt had an uncanny ability to "feel" traps, and avoid walking into them. When something was wrong, Kurt would often get a bad feeling. When John-117 and Kurt were on separate teams during training, John often lost as a result of Kurt's "funny feelings". His teammates grew to view this as an asset, trusting Kurt's instincts and common sense.[6]

Kurt was among the best of the Spartan-IIs, right next to John-117 in skill and superiority. Kurt, Fred-104, Fhajad-084, Musa-096 and Serin-019 are the only Spartan-IIs to become officers. Kurt was promoted to Lieutenant Commander, "courtesy" of Colonel Ackerson.

He last donned his MJOLNIR armor during SPARTAN-III Alpha Company's introduction to the program but chose not to wear it since, although he maintained the suit in a pristine condition in a safe within his private quarters. Lucy-B091 was thoroughly surprised when she saw the armor, suggesting that Kurt had not shown it even to his senior NCOs.[15]

"Ambrose", the pseudonym assigned to Kurt by Ackerson, comes from the late Latin name Ambrosius, which was derived from the Greek name Αμβρόσιος (Αmbrosios) meaning "immortal"; this could reference the fact that Spartans are never marked as KIA in an attempt to uphold the belief that Spartans never die. This is appropriate, as his last words were, "Die? Didn't you know? Spartans never die." From a real-world perspective, Kurt was likely named in honor of the late Stephen Ambrose, the author of the historical biography Band of Brothers, which was later adapted into an HBO miniseries. The name of the camp where Kurt trained the SPARTAN-IIIs, Camp Currahee, is a reference to Band of Brothers.

Kurt and Jorge-052 were the only SPARTAN-IIs known to have been involved in the SPARTAN-III program. Coincidentally, their Spartan tags are consecutive integers.

"Kurt" is one of the name options for customized loadouts in Halo: Reach, along with the members of NOBLE Team and several SPARTAN-IIs.[29]